Feed finger



May 27, 1930. c. F. MINNIER ET AL v1,760,860

FEED FINGER Filed May l, 1928 wif FHQ WMMMBLIQ 6 @mfG/y 310mm Patented May 27, 1930 Matt CHARLES r. Minitrue am)` Barmenia Benina, or rraiairsuaa, rnNNsYLvaNIA;

sein DANIEL Assiettes. To sain Minn-inn; CENTRAL TRUST COMPANY, ois` HARRIS- BURG, PENNSYLVANIA, iiXnCUafoa oF' sein "Minuten, niacnasan FEED amena Our invention relates to feed ngers for operating on bar or strip material, and is parof this type consists of a set of hardened steel jaws which res'iliently hold the bar stock in position in the -rear of a collet, but allow it to be forced rearwardly whenever the collet jaws are released. l/Vhen stoel; is fed Vforward through the jaws of the collet and into engagement with theusual stop employed in such machines, it is frequently the case that the stool; is not fed far enough to produce part-s of the proper length' and unless the fee-ding mechanism is very carefully adjusted, the engagement of the stock with Vthe stop causes considerable pressure to be exerted upon this stock and thereby causes rapid wear .on the feeding cam. It is alsov a fact that the usual type of feed finger is very short lived and by its `pressure on the stock produces grooves and marks therein so that the parts turned out by the machine are defective.' Y

Among the objects of our invention are the provision of a feed finger which will allow bar stock to feed Yin one direction but to resist its movement in the other direction; to prevent marring of the stock; to render the finger sufliciently resilient to ensurea full feed during each movement, but to reduce wear on the feeding'cam; and to provide means whereby the finger may be manipulated to release the stock without removing the feed tube from the machine. Y Y.

We will now describe two forms of feed finger embodying our invention and then point out the novel features thereof claims.

In the accompanying drawings:

Figure lis a view partly in elevation and partly in section showing the relation of our feed nger to a conventional automatic screw machine;

Fig. 2 is a vertical sectional view o'f one form of feed finger,' the parts being shown in a position to grip a bar of stock; y

Fig. 3 is a view similar to Fig. 2 with the bar in retracted position;

Fig. 4 is a vertical sectional view of a modi- Application filed Ifay 1, 1828. -Serial No.V 274,326.

fied form of feed finger withthe parts in po'- sition to grip a bar of stock; f Fig. 5 is 'a view similar to Fig. e with the parts locked in position with the bar of stock released; and' Y Fig..6 is adetail view of the locking ring employed in the form of feed finger shown in Figures l and 5. n

Similar reference characters refer to simi'- lar parts in each of the several views.

ln Figure l the reference character l designates the usual spindle of `a conventional automatick screw machine. -As here shown this spindle is supported in bearing. boxes 2 and 3 and is actuatedby Idriving pulleysy 4. Within the spindle l and projecting4 rear'- wardly therefromis a feed tube 5 carrying at its forward'end ap feed finger 6.

. Then operated in the usual mannerbar stock is fed through the tube until itenters y and is gripped by the feed finger 6.,l lThe spindle l also carries at its forward end a spring collet 7 which is adapted to be closed by a tapered sleeveS. Inasmuch as the operating mechanism for this collet is not apart v i of ourV invention and is well known in the art, further description will not be necessary. It will be sufcient to` state that bary stock is fed forward through the feed tube 5 and the feed finger 6 vso that it projects through the jaws of the spring collet 7 which is then closed and yholds the stock in position whiley being worked upon by the usual cutting tools.

As shown in Figure 2 our feedffinger coin- Aprises a hollow tubular shell 9 which is -par-` l tiallycl'osed'at its forwardend, but is open at the rear end and closely engages with the reduced Jportion ofl a plug 10 and is secured thereto by any suitable means such as a pin 9a* The rear end ofpluglO is threaded at 10aL so that the finger can be secured to the feed tube in the usual manner. This plug contains sockets 2l into which' a tool may be inserted forthe purpose of screwing the finger into position. Slidably mounted within the shell 9 is a tubular member 11 having an iiiclined inner wall 12 which diverges outwardly toward the forward end of the shell. This member is normally biasedto the position shown in F 2 by a coil spring 13 which reacts against a collar 14 also carried within rearward direction;

the shell 9 and engaging the forward end of plug 10 adjacent to a countersunk portion 17.

Within the member 11 is an elongated tubular sleeve having an annular flange 16 engaging the collar 14. This sleeve 15 contains a plurality of spaced apertures 18 near its forward end shaped to accommodate balls 19. Any suitable number of these balls may be provided, it only beingnecessary that theyy be symmetrically placed around the periphery of the sleeve 15. As here shown a sma-ll collar embraces the forward end of sleeve 15 and engages the forward end of member 11 so as to prevent the balls 19 from ever leaving their proper position within the apertures It will be clear from an inspection of Fig. 3 that under normal conditions the spring 13 will force the member 11 forward within the shell 9 so that the balls 19 engage with the inclined wall 12 of this member and are thereby forced inwardly toward the aXis of sleeve 15 and lock the bar B against movement in a lVhen, however, the finger is drawn backward these balls roll up the diverging wall 12 sufficiently to release the bar and to allow the finger to slide backward over the stock. Although when in locked position no relative movement between the locking halls 19 and the bar of stock B' canoccur, yet due to the resiliency of spring 13, this bar may move rearwardly for a short distance carrying with it sleeve 15, balls 19 and mem-V ber 11 as clearlyshown inFigure 3. This resiliency is an important feature of our invention because it makes it possible for us to ""eed the bar of stock forward against the stop through a distance slightly in excess ofthe length of material required, and to hold it resiliently in this position. This causes a full feed during each stroke of thefeeding mechanism, eliminates the wear on the parts occasioned by moving the stock backward through the finger. and prevents breakage.

By suitably proportioning the countersunk portion 17 the finger may be designed to permit the bar of stock to move'V backward through the finger when the sleeve 15 is pushed back into portion 17 of plug 10 far enough to release balls 19 (see Fig. 3). The parts will be returned to gripping position whenever the excess pressure is removed from spring 13.v

During` the operation of machines of the type with which we are concerned, it sometimes hannens thaty when a bar of stockV is nearly used up, the` stock iswithdrawn from the feed finger, but extends back far enough 'from the collect so that upon the next forward Y strokeV of the feeding mechanism the feed finger strikes'against the rear end of the bar. Inasmuch as the bar is being rigidly held by the collect, breakage of some of the parts frequently occurs. Such breakage can not occur with our feed linger because as the finger moves forward, the rear end ofthe bar enters the sleeve 15 and is again clutched by the balls 19 ready to feed forward upon the i wear on this cam and greatly reduces breakage.

The feed nger shown in Figures 2 and 3 provides for movement of the stock in onel direction only, and it does not allow the gripping means to be released. Under some conditions it is desirable'to have this finger arranged` to permit the stock to be removed from therear of the feed tube without removing the finger from the machine and for this purpose wev provide the mechanism shown in Figures 4 and 5. Y

Referring now to Figure 4, the device there shown comprises a shell 22 similar to the shell 9 of Fig. 2, but provided in the central portion thereof with an annular groove 29 eX- tending around its inner wall. Fitted into the rear end of this shell is a'plug 34 having a deep countersunk portion 35 and a rea-rwardly extending threaded portion 34a. As here shown, the plug 34 is held within the shell 22 by means of pins 36, and is provided with openings 21 for the accommodation of the tool used in screwing the finger into the feed tube. Slidably mounted within the shell 22 is a tubular member 23 similar to the member 11 hereinbefore described, butpro'- vided with a cut-out portion to accommodate `outer surface of the sleeve to the bottom of the groove. Mounted within the groove 25 is a locking ring 26 (shown in detail in Fig. 6), having. a small project-ing lug 27.vv Abutting the side of ring 26, remote from the lug 27, is the leaf spring 23 having a project'- ing tongue 28a and secured to the member 23 by suitable means such as a screw 31. Fitted within the shell 22 and contacting with the rear end of member 23 vis a stepped ring 37 which closes the rear end of member'23 in proximity to the locking ring 26. The member 23 is normally biased to the forward end of shell 22 by means of a spring '13 reacting dim.

against an annular collar 3() whichiits against the forward-end of plug 34. Also mounted within vthe countersunk portion of plug 84 is a small spring 32 which functions in amanner which will'be hereinafter described.

From an inspection of Fig. 4, it will now vbe clear that when rod B is forced through the o enino' in luo` v34 and through the tubular` b D :D

shell 24, the spring 13 will force the member 23 forward so that the balls 19, riding down the inclined wall of the member are forced into contact with the bar B so as to prevent its being` withdrawn rearwardly`I but to allow it to slide forward freely. When the bar is drawn forwardly the balls rotate and move up the inclined surface of the wall of member 23 to a release position.

Under some circumstances it is desirable to release the gripping mechanism so that the bar of stock may be withdrawn from the rear of the feed tube and to so arrange the parts that the locking mechanism may be released without withdrawing the feed tube from the machine. As shown in Figure 5 the locking means is shown in operative position with the bar B released and free to slide withvin the sleeve 24. It will be noted from this figure that when the bar B has been withdrawn from the position shown in Figure 4, the member 23 and sleeve 24 are drawn baclrward against the tension of spring 13 until the small lug 2T on locking ring 26 is above the groove 29 on the inner wall of shell 22. Vhen the parts reach this position, the top side of locking ring 26 drops into the groove 25 in the surface of sleeve 24 and lug 27 is forced into groove 29 and is held there by the tension of the fiat spring 28. When it is desired to release this locking mechanism the bar of stock B may be withdrawn far enough so that the front end of the bar can be tilted slightly and to engage the ,rear end of flange 33 on tube 24. Vhen the tube 24 is moved forward the top side of ring 26 rides upon the rear inclined shoulder of groove 25, thereby raising the lug 27 from groove 29 and free- Y ing member 23 and sleeve 24 which are then moved forward by spring 13 to the position shown in Fig. 4.

l/Vhen the parts are locked inthe release position as sh-own in Figure 5 it is essential that sufiicient tension be placed on the rear en'd of sleeve 24 to release the balls 19 and move them out of Contact with bar B. For this purpose we provide the small coil spring 32 which is capable of exerting a small force against the sleeve 24 suilicientto move theballs 19 forward and up the inclined wall of member 23, but insuicient to cause locking ring 26 to be released. VIt will be apparent that the spring 32 must be materially smaller than the spring 13 in order to prevent the locking means from being released prematurely. By making the opening through plug 34 slightly larger than the size of stock with which it is to beused and making the bore of sleeve 24 slightly smaller in diameter than the opening through this plug, a projecting shoulder is formed against which the stock may be pushed in order to release the locking mechamsm.y

lf it is not desirable to use the locking means,- a plug of the type shown in Figures 2 and 3 may be fused to replace the plug 34 so as to prevent sleeve 24 from being moved rearwardly farenough to allow lug'27 to enter groove 29, and with this combination the feed linger shown in Figures 4 and 5 can be used without'the locking means. f

rlhe 4feed linger shown in Figures 4 and 5 not only has the advantages ofthe finger `shown in Figures 2 and 3, ybut in addition thereto maires it possible to release the stock from the feed linger and to'withdraw fthe stock for making any required adjustments with-out stopping the .machine kor 'removing the yfeed tube.

`Although we have herein shown and described only two forms of feedV finger embodying our 1`nvention, it is obvious that various changes 'and modifications may be made within the scope of the appended claims without departing from the spirit land scope of our invention. 1

1. A feed finger for metal-Working machines comprising, a metal shell; a y.tubular member within said shell, said member having an inclined inner wall diverging toward kone end of said shell; a sleeve slidable within said member, said sleeve having a plurality of apertures therein; balls within said apertures and cooperating with said inclined Wall; and a spring. within said shell for normally forcing said member forward to move said balls to operative position.

2. A stock feed finger for metal-working machines comprising, a metal shell, said .member having a locking and a releasing position; a tubular member within said shell; a' sleeve within said member; a plurality of balls carried in said sleeve means for biasing saidmember to locking position to force said balls radially inward; and means for locking said member in release position, .whereby said balls are released. v

3. A feed linger for metal-working machines comprising a metal shell; a tubular member within saidv shell, said member having an inclined wall diverging toward one end thereof; a sleeve. within said member, said sleeve having a plurality of spaced apertures therein; a ball in each of said apertures; andmeans within said shell for forcing said balls andthe inc-lined` wall of said member into engagement. v

Vv4. A feed .finger for metal-working machines comprising a metal shell having an annular groove therein; a tubular member within said shell, said member having an ng-r-l ner inclined wall; a sleeve within said member and having a plurality of spaced apertures therein; a ball in each of said aperf tures; a spring for forcing said Vmember into Contact with said balls and thereby moving them to work-engaging position; a locking ring embracing said sleeve; and a spring for forcing a portion of said locking ring into the Y -ity of balls cooperating therewith; and

means operated by movement of the stock within the finger for locking said work-engaging means in release position. Y

7 The combination with the feed tube of an automatic screw machine, of a. stock feed finger secured to the forward end of said tube and comprising a metal shell; stock gripping meanswithin said shell, said means comprising a tubular member having an inclned wall and a plurality of balls cooperating with said wall to grip or release a bar of stock; means for locking said gripping means in release position; and means whereby said locking means may be released from the rear of said feed tube.

8. A feed finger for automatic screw machines, comprising a metal shell; a tubular member within said shell, said member having an inclined inner wall; a sleeve within said member; a plurality of work-engaging balls carried by said sleeve and cooperating with said inclined wall; and means for yieldably urging said wall into Contact with said balls.

9. The combination with the feed tube of an automatic screw machine, of a stock feed finger carried at the forward end of said tube and comprising a metal shell; gripping means within said shell for allowing stock to pass therethrough in one direction only; means for locking said gripping means in release position; and means whereby said locking means may be released with the feed tube in the machine.

10. ln a device of the character described, a metal shell; a movable sleeve disposed in said shell; work-engaging members carried by said sleeve; and a spring actuated movable member having an inclined surface for progressively moving said members to workengaging position.

1l. ln a device of the character described,

In testimony whereof we have signed *our names to this specification.

CHARLES F. MINNIER BENJAMIN M. DANIEL.

CERTIFICATE or CoRREoTioN.

Patent No. 1,760,861). A A Grantee May 27, 1930, to

CHARLES F. MINNIER 11T AL. I

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, lines 3.08 to lll), claim 2, strike out the comma and words said member having a locking and a releasing position" anti insert the same to follow after the word "shell" and betore the semi-colon in line H0; and that the said Letters Patent should be read with this correotion therein that the same may conform to the record of the case in the Patent Oft'ice.

Signed and sealeri this 24th day of lune, A. D. 1930.

M. J. Moore, (Seal) Acting Geminissioner of Patents. 

